1. Field of Endeavor
The present disclosure relates to heat exchangers, and more particularly to rollers for forming heat transfer elements used in such heat exchangers, for transferring heat.
2. Brief Description of the Related Art
Heat exchangers, such as rotary regenerative air preheaters, include various heat transfer elements stacked therein to transfer heat from a hot gas stream to a cold gas stream. For effective transfer of heat, the heat transfer elements include one or more geometric characteristics, such as undulations, corrugations, notches and flats. Generally, such characteristics are formed by roll pressing metallic sheets or plates between a pair of metallic rollers, which include one or more similar characteristics across its circumference. The characteristics formed on the roll pressed metallic sheet correspond to characteristics across the circumference of press rollers.
The metallic rollers with said characteristics are generally produced by machining the rollers across its circumference. Machining the said characteristics or its various combinations on metallic rollers may be very cumbersome, tedious and time taking job, apart from being uneconomical. Further, such machining of rollers generally also limits the characteristics to current machining technologies and practices and the geometry of uninterrupted characteristics. Moreover, loading and unloading of such metallic rollers on roller pressing machines for forming the heat transfer elements with varying characteristics may also add to its overall tediousness and time.